1. Field of the Invention
The present invention relates to the field of sand and other solids removal from wellbores. More particularly, the invention relates to an apparatus and method for hydraulic withdrawal of sand and other solids into a housing for wireline removal from a wellbore.
2. Description of Related Prior Art
Sand and other solid particulate materials are produced from certain subsurface geologic formations into a wellbore. The sand can accumulate within the wellbore to restrict fluid production and to prevent movement of workover and other well tools within the wellbore. Well screens and gravel packing techniques restrict sand movement into the wellbore, however these techniques are expensive and do not fully prevent sand migration into the wellbore. Representative examples of such techniques are disclosed in U.S. Pat. No. 4,623,022 to Chakrabarty et al. (1986), in U.S. Pat. No. 4,681,163 to Guidry et al. (1987), in U.S. Pat. No. 5,036,920 to Cornette et al. (1991), and U.S. Pat. No. 5,076,355 to Donovan et al. (1991), reissued 1993 as RE 34,451.
Other tools have been developed for removing debris from wellbores. U.S. Pat. No. 5,224,548 to Dankovich et al. (1993) disclosed an auger for clearing and retrieving debris from a wellbore. U.S. Pat. No. 5,327,974 to Donovan et al. (1994) disclosed another technique for increasing the fluid velocity to entrain debris for removal from a wellbore. Other techniques use pressure washing and fluid jet techniques to wash sand from the interior of a wellbore, or use coiled tubing tools to clear blocked wellbores.
Although coiled tubing tools effectively remove sand and other debris from wellbores, coiled tubing operation is expensive and requires significant equipment. A wireline sand removal tool was disclosed in U.S. Pat. No. 3,900,074 to Lee (1975), wherein a rotatable bit operated with an inner and outer tube to capture wellbore sand for removal to the well surface. The mechanical operation of such tool limits the reliability of this technique, and can fail due to wear on the mechanical components. A need, therefore, exists for an improved apparatus and technique for removing sand from wellbores.